Delete label keys and values

src/lib.rs

@@ -43,6 +43,16 @@ impl Board {
         }
     }
 
+    pub fn remove_label_key(&mut self, key: &str) {
+        self.labels.remove(key);
+    }
+
+    pub fn remove_label_value(&mut self, key: &str, value: &str) {
+        if let Some(l) = self.labels.get_mut(key) {
+            l.remove(value);
+        }
+    }
+
     pub fn add_edge(&mut self, from: usize, to: usize) {
 	let node = self.nodes.get_mut(&from).expect("Could not find node");
 	node.edges.insert(to);